ECRIS2018 - List of Authors (Galatà, A.)

Paper	Title	Page
TUB2	Plasma Heating and Innovative Microwave Launching in ECRIS: Models and Experiments	63
	G. Torrisi, G. Castro, L. Celona, S. Gammino, D. Mascali, G. Mauro, M. Mazzaglia, E. Naselli, G. Sorbello INFN/LNS, Catania, Italy A. Galatà INFN/LNL, Legnaro (PD), Italy E. Naselli Catania University, Catania, Italy
	Microwave-to-plasma coupling in ECRIS has been based on the classic scheme of waveguide-to-cylindrical plasma cavity matching. Optimization has been often obtained by empirical adjustments leading to an oversimplified model, obtaining however satisfying performances. In order to overcome the ECR-heating paradigm, on-purpose design of launchers' setup adequate diagnostics have to be developed. This paper describes three-dimensional numerical simulations and Radio Frequency (RF) measurements of wave propagation in the microwave-heated magnetized plasmas of ion sources. Moreover, driven by an increasing demand of high frequency ECR ion sources, innovative ideas for the geometry for both the plasma chamber and the related RF launching system - in a plasma microwave absorption-oriented scenario are presented. Finally, the design of optimized launchers enabling single-pass power deposition, not a'ected by cavity walls effects, are described.
	Slides TUB2 [50.695 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2018-TUB2
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUB3	A Possible Optimization of Electron Cyclotron Resonance Ion Sources Plasma Chambers	67
	C.S. Gallo, A. Galatà INFN/LNL, Legnaro (PD), Italy D. Mascali, G. Torrisi INFN/LNS, Catania, Italy
	In the resonant cylindrical cavities of Electron Cyclotron Resonance Ion Sources (ECRIS), microwave fields are used to generate and sustain the plasma. Normally, resonant modes of a higher order than the fundamental one are excited, due to the high frequency used compared to the dimensions of the plasma chambers: this can lead to small electric fields on the resonant surface, translating in low electrons energy and poor source performances. In this paper, we propose a possible modification of the conventional plasma chambers, resulting from an electromagnetic study carried out on a Caprice-type full permanent magnet ECRIS. Such modification implies the excitation of a "length-independent" resonant mode, having an intense and homogeneous electric field on the plasma chamber axis. This characteristic makes the modification suitable to be applied to numerous ECR sources. The positive effect on the plasma electrons density distribution will be also shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2018-TUB3
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP06	Progresses in the Installation of the SPES-Charge Breeder Beam Line	85
	A. Galatà, L. Bellan, J. Bermudez, G. Bisoffi, D. Bortolato, M. Comunian, A. Conte, M. De Lazzari, F. Francescon, F. Gelain, D. Marcato, M.O. Miglioranza, M.F. Moisio, E. Munaron, S. Pavinato, D. Pedretti, A. Pisent, M. Roetta, C. R. Roncolato, M. Rossignoli, G. Sevarese INFN/LNL, Legnaro (PD), Italy V. Andreev ITEP, Moscow, Russia M.A. Bellato INFN- Sez. di Padova, Padova, Italy
	Since fall 2017, the ADIGE (Acceleratore Di Ioni a Grande carica Esotici) injector of the SPES (Selective Production of Exotic Species) project entered the installation phase. The injector includes an ECR-based charge breeder (SPES-CB) and its complete beam line, as well as a newly designed RFQ, to allow the post-acceleration of the radioactive ions produced in the so-called Target-Ion-Source system. The injector has different peculiarities, deriving from particular needs of SPES: a complete electrostatic beam line equipped with a 1+ source for test purposes, and a unique Medium Resolution Mass Spectrometer (MRMS, R~1/1000), mounted downstream the SPES-CB, to clean the radioactive beam from the contaminants induced by the breeding stage. This contribution reports about the status of the installation of the injector, describing the various technical solution adopted, and giving a realistic planning for the commission and following operation of its main parts.
	Poster TUP06 [0.944 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2018-TUP06
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP14	Multi-Diagnostic Setup to Investigate the Two-Close-Frequency Phenomena	115
	S. Biri, Z. Perduk, R. RÃ¡cz ATOMKI, Debrecen, Hungary C. Caliri, G. Castro, L. Celona, S. Gammino, D. Mascali, M. Mazzaglia, E. Naselli, F.P. Romano, G. Torrisi INFN/LNS, Catania, Italy A. Galatà INFN/LNL, Legnaro (PD), Italy J. Pálinkás University Debrecen, Debrecen, Hungary F.P. Romano IBAM-CNR, Catania, Italy
	While the mechanism is still not clear, the beneficial effect (higher intensity of highly charged ions, stable plasma conditions) of the second microwave injected to the ECR plasma was observed in many laboratories, both with close and far frequencies. Due to the complexity of the phenomena (e.g. interaction of resonant zones, damped instabilities) complex diagnostic methods are demanded to understand its mechanism better and to fully exploit the potential hidden in it. It is a challenging task since complex diagnostics methods require the arsenal of diagnostic tools to be installed to a relatively small size plasma chamber. Effect of the injected second 13.6-14.6 GHz microwave to the 14.25 GHz basic plasma has been investigated by means of soft and (time-resolved) hard X-ray spectroscopy, by X-ray imaging and by probing the rf signals emitted by the plasma. In order to separate the source and position of different X-ray photons special metallic materials for the main parts of the plasma chamber were chosen. A detailed description and explanation of the full experimental setup and the applied non-invasive diagnostics tools and its roles are presented in this paper.
	Poster TUP14 [2.615 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2018-TUP14
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP27	Numerical Simulations of Magnetically Confined Plasmas	152
	A. Galatà, C.S. Gallo INFN/LNL, Legnaro (PD), Italy D. Mascali, G. Torrisi INFN/LNS, Catania, Italy
	Since 2012, the INFN ion source group has been undertaking an intense activity on numerical modelling of magnetically confined plasmas, presently carried out in the framework of the PANDORA project. The aim is the development of a predictive tool for the design of Electron Cyclotron Resonance (ECR) Ion Sources or Traps and ECR-based Charge Breeders, able to determine spatial density and energy distributions for both electrons and ions. The work mainly concerns the study of two aspects: on one hand, the interaction of an ion beam with a magnetized plasma; on the other hand, the microwave-to-plasma coupling, including the 3D plasma electrons dynamics in the confinement magnetic field and intra-particles collisions. This contribution describes the state-of-the-art of the work on both the fronts: an overview of the beam-plasma interaction, showing the latest results about the ECR-plasma density fine structure, as well as electron spatial temperature distribution will be shown.
	Poster TUP27 [1.254 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2018-TUP27
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEA5	Effect of the Two-Close-Frequency Heating to the Extracted Ion Beam and to the X-Ray Flux Emitted by the ECR Plasma	165
	R. RÃ¡cz, S. Biri, Z. Perduk ATOMKI, Debrecen, Hungary G. Castro, L. Celona, S. Gammino, D. Mascali, M. Mazzaglia, E. Naselli, G. Torrisi INFN/LNS, Catania, Italy A. Galatà INFN/LNL, Legnaro (PD), Italy J. Pálinkás University Debrecen, Debrecen, Hungary
	Multiple frequency heating has been used since the '90 in ECR ion sources as heating schemes able to improve current intensities especially for highly charged ions. More recently, "Two Close Frequency Heating", where the frequency gap is comparable with the scale-length of the resonance, has been proposed, expected also to be sensitive to the relative waves phase relationship. At ATOMKI - Debrecen a dedicated experiment has been carried out for exploring the effects of the combined frequencies and their relative phase-difference in an argon plasma. The second frequency was finely tuned between 13.6-14.6 GHz with respect to the first one (fixed 14.25 GHz). An optimal frequency gap (in terms of Ar¹¹⁺/A⁶⁺ beam currents ratios) has been experimentally found, in agreement with the theory; the optimal power balance (total RF power was 200 W) between the two frequencies has been determined empirically. A weak but clear effect of the relative phase shift has been observed. Each configuration has been characterized by a multi-diagnostics set-up: HPGe and SDD detectors were used for the X-rays, a RF probe was introduced inside the plasma chamber to detect the radio-emission from the plasma.
	Slides WEA5 [4.394 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2018-WEA5
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRB2	Impact of the Two Close Frequency Heating on ECRIS Plasmas Stability	214
	E. Naselli, C. Caliri, G. Castro, L. Celona, S. Gammino, D. Mascali, M. Mazzaglia, F.P. Romano, G. Torrisi INFN/LNS, Catania, Italy S. Biri, Z. Perduk, R. RÃ¡cz ATOMKI, Debrecen, Hungary A. Galatà INFN/LNL, Legnaro (PD), Italy E. Naselli Catania University, Catania, Italy J. Pálinkás DU, Debrecen, Hungary F.P. Romano IBAM-CNR, Catania, Italy
	Several experiments have recently demonstrated that plasma instabilities are powerful limiting factors to the flux of highly charged ion beam extracted from ECRIS. One of the methods for damping the instabilities is to feed the plasma in two frequency heating mode. Since the fundamental physical mechanism is still unclear (diffusion in velocity space? additional confinement?), a deeper experimental investigation is necessary, using multi-diagnostics setups. At ATOMKI-Debrecen the effect on the plasma instabilities of an argon plasma in a 'Two Close Frequencies' scheme has been explored. Spectra of radio-emission from the plasma have been collected for different frequency gaps and relative power balances. The measurements show the plasma self-emitted radiation comes out from the internal plasma (i.e. around the lower frequency) but the instability damping can be effective for some specific combinations of frequency-gap and power balance. Radiofrequency spectra have been collected simultaneously to time-resolved X-ray measurements, triggered by RF bursts produced by the instabilities and detected via a microwave diode connected to a plasma-chamber-immersed multi-pin RF probe.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2018-FRB2
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Plasma Heating and Innovative Microwave Launching in ECRIS: Models and Experiments

63

G. Torrisi, G. Castro, L. Celona, S. Gammino, D. Mascali, G. Mauro, M. Mazzaglia, E. Naselli, G. Sorbello
INFN/LNS, Catania, Italy
A. Galatà
INFN/LNL, Legnaro (PD), Italy
E. Naselli
Catania University, Catania, Italy

Microwave-to-plasma coupling in ECRIS has been based on the classic scheme of waveguide-to-cylindrical plasma cavity matching. Optimization has been often obtained by empirical adjustments leading to an oversimplified model, obtaining however satisfying performances. In order to overcome the ECR-heating paradigm, on-purpose design of launchers' setup adequate diagnostics have to be developed. This paper describes three-dimensional numerical simulations and Radio Frequency (RF) measurements of wave propagation in the microwave-heated magnetized plasmas of ion sources. Moreover, driven by an increasing demand of high frequency ECR ion sources, innovative ideas for the geometry for both the plasma chamber and the related RF launching system - in a plasma microwave absorption-oriented scenario are presented. Finally, the design of optimized launchers enabling single-pass power deposition, not a'ected by cavity walls effects, are described.

Slides TUB2 [50.695 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2018-TUB2

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUB3

A Possible Optimization of Electron Cyclotron Resonance Ion Sources Plasma Chambers

67

C.S. Gallo, A. Galatà
INFN/LNL, Legnaro (PD), Italy
D. Mascali, G. Torrisi
INFN/LNS, Catania, Italy

In the resonant cylindrical cavities of Electron Cyclotron Resonance Ion Sources (ECRIS), microwave fields are used to generate and sustain the plasma. Normally, resonant modes of a higher order than the fundamental one are excited, due to the high frequency used compared to the dimensions of the plasma chambers: this can lead to small electric fields on the resonant surface, translating in low electrons energy and poor source performances. In this paper, we propose a possible modification of the conventional plasma chambers, resulting from an electromagnetic study carried out on a Caprice-type full permanent magnet ECRIS. Such modification implies the excitation of a "length-independent" resonant mode, having an intense and homogeneous electric field on the plasma chamber axis. This characteristic makes the modification suitable to be applied to numerous ECR sources. The positive effect on the plasma electrons density distribution will be also shown.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2018-TUB3

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP06

Progresses in the Installation of the SPES-Charge Breeder Beam Line

85

A. Galatà, L. Bellan, J. Bermudez, G. Bisoffi, D. Bortolato, M. Comunian, A. Conte, M. De Lazzari, F. Francescon, F. Gelain, D. Marcato, M.O. Miglioranza, M.F. Moisio, E. Munaron, S. Pavinato, D. Pedretti, A. Pisent, M. Roetta, C. R. Roncolato, M. Rossignoli, G. Sevarese
INFN/LNL, Legnaro (PD), Italy
V. Andreev
ITEP, Moscow, Russia
M.A. Bellato
INFN- Sez. di Padova, Padova, Italy

Since fall 2017, the ADIGE (Acceleratore Di Ioni a Grande carica Esotici) injector of the SPES (Selective Production of Exotic Species) project entered the installation phase. The injector includes an ECR-based charge breeder (SPES-CB) and its complete beam line, as well as a newly designed RFQ, to allow the post-acceleration of the radioactive ions produced in the so-called Target-Ion-Source system. The injector has different peculiarities, deriving from particular needs of SPES: a complete electrostatic beam line equipped with a 1+ source for test purposes, and a unique Medium Resolution Mass Spectrometer (MRMS, R~1/1000), mounted downstream the SPES-CB, to clean the radioactive beam from the contaminants induced by the breeding stage. This contribution reports about the status of the installation of the injector, describing the various technical solution adopted, and giving a realistic planning for the commission and following operation of its main parts.

Poster TUP06 [0.944 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2018-TUP06

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP14

Multi-Diagnostic Setup to Investigate the Two-Close-Frequency Phenomena

115

S. Biri, Z. Perduk, R. RÃ¡cz
ATOMKI, Debrecen, Hungary
C. Caliri, G. Castro, L. Celona, S. Gammino, D. Mascali, M. Mazzaglia, E. Naselli, F.P. Romano, G. Torrisi
INFN/LNS, Catania, Italy
A. Galatà
INFN/LNL, Legnaro (PD), Italy
J. Pálinkás
University Debrecen, Debrecen, Hungary
F.P. Romano
IBAM-CNR, Catania, Italy

While the mechanism is still not clear, the beneficial effect (higher intensity of highly charged ions, stable plasma conditions) of the second microwave injected to the ECR plasma was observed in many laboratories, both with close and far frequencies. Due to the complexity of the phenomena (e.g. interaction of resonant zones, damped instabilities) complex diagnostic methods are demanded to understand its mechanism better and to fully exploit the potential hidden in it. It is a challenging task since complex diagnostics methods require the arsenal of diagnostic tools to be installed to a relatively small size plasma chamber. Effect of the injected second 13.6-14.6 GHz microwave to the 14.25 GHz basic plasma has been investigated by means of soft and (time-resolved) hard X-ray spectroscopy, by X-ray imaging and by probing the rf signals emitted by the plasma. In order to separate the source and position of different X-ray photons special metallic materials for the main parts of the plasma chamber were chosen. A detailed description and explanation of the full experimental setup and the applied non-invasive diagnostics tools and its roles are presented in this paper.

Poster TUP14 [2.615 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2018-TUP14

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP27

Numerical Simulations of Magnetically Confined Plasmas

152

A. Galatà, C.S. Gallo
INFN/LNL, Legnaro (PD), Italy
D. Mascali, G. Torrisi
INFN/LNS, Catania, Italy

Since 2012, the INFN ion source group has been undertaking an intense activity on numerical modelling of magnetically confined plasmas, presently carried out in the framework of the PANDORA project. The aim is the development of a predictive tool for the design of Electron Cyclotron Resonance (ECR) Ion Sources or Traps and ECR-based Charge Breeders, able to determine spatial density and energy distributions for both electrons and ions. The work mainly concerns the study of two aspects: on one hand, the interaction of an ion beam with a magnetized plasma; on the other hand, the microwave-to-plasma coupling, including the 3D plasma electrons dynamics in the confinement magnetic field and intra-particles collisions. This contribution describes the state-of-the-art of the work on both the fronts: an overview of the beam-plasma interaction, showing the latest results about the ECR-plasma density fine structure, as well as electron spatial temperature distribution will be shown.

Poster TUP27 [1.254 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2018-TUP27

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEA5

Effect of the Two-Close-Frequency Heating to the Extracted Ion Beam and to the X-Ray Flux Emitted by the ECR Plasma

165

R. RÃ¡cz, S. Biri, Z. Perduk
ATOMKI, Debrecen, Hungary
G. Castro, L. Celona, S. Gammino, D. Mascali, M. Mazzaglia, E. Naselli, G. Torrisi
INFN/LNS, Catania, Italy
A. Galatà
INFN/LNL, Legnaro (PD), Italy
J. Pálinkás
University Debrecen, Debrecen, Hungary

Multiple frequency heating has been used since the '90 in ECR ion sources as heating schemes able to improve current intensities especially for highly charged ions. More recently, "Two Close Frequency Heating", where the frequency gap is comparable with the scale-length of the resonance, has been proposed, expected also to be sensitive to the relative waves phase relationship. At ATOMKI - Debrecen a dedicated experiment has been carried out for exploring the effects of the combined frequencies and their relative phase-difference in an argon plasma. The second frequency was finely tuned between 13.6-14.6 GHz with respect to the first one (fixed 14.25 GHz). An optimal frequency gap (in terms of Ar¹¹⁺/A⁶⁺ beam currents ratios) has been experimentally found, in agreement with the theory; the optimal power balance (total RF power was 200 W) between the two frequencies has been determined empirically. A weak but clear effect of the relative phase shift has been observed. Each configuration has been characterized by a multi-diagnostics set-up: HPGe and SDD detectors were used for the X-rays, a RF probe was introduced inside the plasma chamber to detect the radio-emission from the plasma.

Slides WEA5 [4.394 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2018-WEA5

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRB2

Impact of the Two Close Frequency Heating on ECRIS Plasmas Stability

214

E. Naselli, C. Caliri, G. Castro, L. Celona, S. Gammino, D. Mascali, M. Mazzaglia, F.P. Romano, G. Torrisi
INFN/LNS, Catania, Italy
S. Biri, Z. Perduk, R. RÃ¡cz
ATOMKI, Debrecen, Hungary
A. Galatà
INFN/LNL, Legnaro (PD), Italy
E. Naselli
Catania University, Catania, Italy
J. Pálinkás
DU, Debrecen, Hungary
F.P. Romano
IBAM-CNR, Catania, Italy

Several experiments have recently demonstrated that plasma instabilities are powerful limiting factors to the flux of highly charged ion beam extracted from ECRIS. One of the methods for damping the instabilities is to feed the plasma in two frequency heating mode. Since the fundamental physical mechanism is still unclear (diffusion in velocity space? additional confinement?), a deeper experimental investigation is necessary, using multi-diagnostics setups. At ATOMKI-Debrecen the effect on the plasma instabilities of an argon plasma in a 'Two Close Frequencies' scheme has been explored. Spectra of radio-emission from the plasma have been collected for different frequency gaps and relative power balances. The measurements show the plasma self-emitted radiation comes out from the internal plasma (i.e. around the lower frequency) but the instability damping can be effective for some specific combinations of frequency-gap and power balance. Radiofrequency spectra have been collected simultaneously to time-resolved X-ray measurements, triggered by RF bursts produced by the instabilities and detected via a microwave diode connected to a plasma-chamber-immersed multi-pin RF probe.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2018-FRB2

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)